The so-called trust hormone, oxytocin, may not improve the symptoms
of children with autism, a large study led by UNSW researchers has
found.

Professor Mark Dadds, of the UNSW School of Psychology,
says previous research suggested that oxytocin – a hormone with powerful
effects on brain activity linked to the formation of social bonds –
could have benefits for children with the disorder.

“Many parents
of children with autism are already obtaining and using oxytocin nasal
spray with their child, and clinical trials of the spray’s effects are
underway all over the world. Oxytocin has been touted as a possible new
treatment, but its effects may be limited,” Professor Dadds says.

Autism
is a complex condition of unknown cause in which children exhibit
reduced interest in other people, impaired social communication skills
and repetitive behaviours.

To determine its suitability as a
general treatment Professor Dadds’ team conducted a randomised
controlled clinical trial of 38 boys aged between seven and 16 years of
age with autism. Half were given a nasal spray of oxytocin on four
consecutive days.

The study has been accepted for publication in the Journal of Autism and Developmental Disorders.

“We
found that, compared to a placebo, oxytocin did not significantly
improve emotion recognition, social interaction skills, repetitive
behaviours, or general behavioural adjustment,” says Professor Dadds.

“This
is in contrast to a handful of previous smaller studies which have
shown some positive effects on repetitive behaviours, social memory and
emotion processing.

“These studies, however, were limited by
having small numbers of participants and/or by looking at the effects of
single doses of oxytocin on specific behaviours or cognitive effects
while the participants had the oxytocin in their system.

“The
results of our much larger study suggest caution should be exercised in
recommending nasal oxytocin as a general treatment for young people with
autism.”

The boys in the new study were assessed twice before
treatment, three times during the treatment week, immediately afterwards
and three months later, with a parent present. Factors such as eye
contact with the parent, responsiveness, warmth, speech, positive body
language, repetitive behaviours, and recognition of facial emotions were
observed.

Research in people who are healthy shows oxytocin can
increase levels of trust and eye-gazing and improve their identification
of emotions in others.

One likely possibility is that many
children with autism have impaired oxytocin receptor systems that do not
respond properly, Professor Dadds says. But there may be a subgroup of
children for whom oxytocin could be beneficial, and research is needed
to determine who responds to it and how best to deliver it.

The
team includes researchers from UNSW, the University of Melbourne and
Neuroscience Research Australia. The study received funding from the
National Health and Medical Research Council and was carried out at the
Royal Far West facility.

Professor Mark Dadds is Principal Research Fellow of
the National Health and Medical Research Council of Australia, Professor
of Psychology at the University of New South Wales, Sydney Australia,
and Foundation Chair of Parenting Sciences at the Institute of
Psychiatry, Kings College London. He has developed and directed several
national intervention programs for children, youth, and their families,
at risk for mental health problems.